Purl Diver Collection Sea Urchin

I took this picture of a common Sea Urchin in the Florida Keys. Sea urchins have a round and spiny shell, typically from 1 1/4 to 4 inches across. Common colors include black and dull shades of green, olive, brown, purple, blue, and red. They have five-fold symmetry and move slowly by means of hundreds of tiny transparent adhesive tube feet, feeding primarily on algae. The name "urchin" is an old word for hedgehog, which sea urchins resemble. Typical sea urchins have protective spines about 1/2 to 1 1/4 inch long, sometimes sharp. The long spine sea urchin familiar in the tropics, has the longest spines. They are thin and can be from 4 to 12 inches long and very sharp. They inflict a painful wound when they penetrate human skin, but are not themselves dangerous if fully removed. Their roe is a delicacy in many cuisines. They are prehistoric animal, with the earliest fossils dating over 450 million years ago!